camaro05

iTrader: (1)

Hello, I am still trying to figure out what is wrong with my car.
First the problem, The car will idle high (around 700 rpm) and drive at a hgher RPM (2000 @60 mph.) It also wants to die when I don't excelerate slowly from a stop and while driving it will hesitate when I step on the throttle.

To fix this I have done the following... Replace the IAC motor (twice) the first time seemed to fix the probelm for a wheek. I also cleaned the Throttle body verry well. I checked the TPS voltage and tried to reset the minimum idle. I replaced the cap and rotor yesterday and that didn't seem to fix anything. I have also used a bottle of propane to check for vacume leaks. I haven't gotten any trouble codes so I can't figue out what to replace next. I guess I will try the 02 sensor.

Please let me know if there is anything else to check or if I am going to have to take it to a dealer to hook up to a machine or something. thanks

Evan

87tpi7749

It really sounds like you need some scan data. You have hit the important points, TPS & IAC & vacuum leak. Now you need to scan. Most problems like this I've seen as bad TPS or vacuum leak. You don't have to have a trouble code to have a sensor be inaccurate, sensors can be "off" but still outside of code setting parameters. Scan car and look for something that doesn't look right, run the tps through a full sweep, may have a bad spot just off idle.

camaro05

iTrader: (1)

Thanks for the reply, what kinda of scan tool do you recomend? And where is a good place to to buy.
I have checked the TPS but I am not sure I moved the arm the whole way.

87tpi7749

If I were to buy one, I'd look for a used Tech 1, but if you go to the DIY Prom board you can find great information on using a laptop & FREE software to scan your car. You just need a computer, cable & some software.

I would say the second route is a steep learning curve but worth the time. You still need to fix your car now, so I would recommend paying a reputable shop to run a diagnostic test on your car. It will usually cost less tha the parts you put in that don't fix the problem. Be up front with the shop that you need the problem diagnosed & that you will do the repair, tell them exactly how it runs & what you have done to try & fix it. It will help them reach a diagnosis faster. Saving you money in the long run.

edit-
I just looked on ebay GM tech 1, I found a few, decent prices.

90tararebird

iTrader: (4)

Mine was doing same thing and it ended up being the temp sensorinfront of the throttle body. Was explained to me that the ecm always thought that the car was bone cold. Just something to check.

camaro05

iTrader: (1)

thanks to boath of you.

camaro05

iTrader: (1)

Just got a new temp sensor, and wanted to make sure it is the same thing you are talking about. The one I have seems to mount right below the TB on the base intake manifold.

The reason I am checking is because in my Haynes maual it says the temp sensor is in the "left cylinder head"

ZZ28ZZ

The sensor on the left cyl head is for the temp gauge in the dash.
The sensor on the intake is for the ECM.